On Monday, Maxis and EA took SimCity offline to implement their 2.0 patch, which introduced a few new features and fixed a large number of issues. Of course, as patches tend to go on occasion, this one caused a number of unforseen problems.
Users have flocked to reddit and EA's forums to report numerous new bugs that suddenly appeared post-patch. These new issues include unexplainable sewage overloads (which is funny, yet gross), traffic errors, new building construction issues, loading errors, and various audio difficulties.
Neither EA nor Maxis has commented on these new problems yet, but I'm sure some programmer somewhere in one of the buildings is slamming his or her head on a keyboard.